Buggy code:
public final class GsshBuilderWrapper extends BuildWrapper { public static final Logger LOGGER = Logger . getLogger ( GsshBuilderWrapper . class . getName ( ) ) ; @ Extension public static final GsshBuilderWrapper . GsshDescriptorImpl DESCRIPTOR = new GsshBuilderWrapper . GsshDescriptorImpl ( ) ; private boolean disable ; private String serverInfo ; private String preScript ; private String postScript ; private String groupName ; private String ip ; public GsshBuilderWrapper ( ) { } @ DataBoundConstructor public GsshBuilderWrapper ( boolean disable , String serverInfo , String preScript , String postScript ) { } private void initHook ( ) { } @ SuppressWarnings ( "rawtypes" ) @ Override public Environment setUp ( AbstractBuild build , Launcher launcher , BuildListener listener ) throws IOException , InterruptedException { } private boolean executePreBuildScript ( PrintStream logger ) { } private boolean executePostBuildScript ( PrintStream logger ) { } public static void printSplit ( PrintStream logger ) { } public SshClient getSshClient ( ) { } public BuildStepMonitor getRequiredMonitorService ( ) { } private void log ( final PrintStream logger , final String message ) { } public boolean isDisable ( ) { } public void setDisable ( boolean disable ) { } public String getIp ( ) { } public void setIp ( String ip ) { } public String getPreScript ( ) { } public void setPreScript ( String preScript ) { } public String getPostScript ( ) { } public void setPostScript ( String postScript ) { } public String getServerInfo ( ) { } public void setServerInfo ( String serverInfo ) { } public String getGroupName ( ) { } public void setGroupName ( String groupName ) { } public String toString ( ) { } public static class GsshDescriptorImpl extends BuildWrapperDescriptor { public static final Logger LOGGER = Logger . getLogger ( GsshBuilderWrapper . GsshDescriptorImpl . class . getName ( ) ) ; public GsshDescriptorImpl ( ) { } public GsshDescriptorImpl ( Class < ? extends BuildWrapper > clazz ) { } private final CopyOnWriteList < ServerGroup > serverGroups = new CopyOnWriteList < ServerGroup > ( ) ; public ServerGroup [ ] getServerGroups ( ) { } private final CopyOnWriteList < Server > servers = new CopyOnWriteList < Server > ( ) ; public Server [ ] getServers ( ) { } public String getDisplayName ( ) { } public String getShortName ( ) { } @ Override public String getHelpFile ( ) { <START_BUG> return "//plugin//ssh2easy//help.html" ; <END_BUG> } @ Override public BuildWrapper newInstance ( StaplerRequest req , JSONObject formData ) { } @ Override public boolean configure ( StaplerRequest req , JSONObject formData ) { } public boolean doServerGroupSubmit ( StaplerRequest req , StaplerResponse rsp ) { } public boolean doServerSubmit ( StaplerRequest req , StaplerResponse rsp ) { } @ Override public boolean isApplicable ( AbstractProject < ? , ? > item ) { } public ServerGroup getServerGroup ( String groupName ) { } public Server getServer ( String ip ) { } public SshClient getSshClient ( String groupName , String ip ) { } public FormValidation doCheckUsername ( @ QueryParameter String value ) throws IOException , ServletException { } public FormValidation doCheckPort ( @ QueryParameter String value ) throws IOException , ServletException { } public FormValidation doCheckGroupName ( @ QueryParameter String value ) throws IOException , ServletException { } public FormValidation doCheckPassword ( @ QueryParameter String value ) throws IOException , ServletException { } public FormValidation doCheckName ( @ QueryParameter String value ) throws IOException , ServletException { } public FormValidation doCheckIP ( @ QueryParameter String value ) throws IOException , ServletException { } } }

Fix:
return "//plugin//ssh2easy-plugin//help.html" ;